The following summary highlights the findings from prick-puncture skin testing performed on persons 6-74 years of age in the National Health and Nutrition Examination Survey (NHANES) II, 1976-80. The prevalence rate of skin-test reactivity to at least one of eight selected allergens was 20.2 percent for persons ages 6-74 years in the U.S. civilian noninstitutionalized population. Among the individual allergens, ragweed and rye grass had the highest individual rates of reactivity with approximately 10 percent of the population reacting to each one. The age-adjusted prevalence rate of skin-test reactivity to at least one of eight selected allergens in persons ages 6-74 years was higher in men (22.2 percent) than in women (18.4 percent). The age-adjusted prevalence rate of skin-test reactivity to at least one of eight selected allergens was higher in black persons (23.2 percent) than in white persons (19.5 percent), but this difference did not reach statistical significance. Peak reactivity to at least one of eight selected allergens occurred in the group 18-24 years of age. The peak reactivities were 33.3 percent for men and 25.2 percent for women. Reactivity rates were lower in the younger and older age groups. Ragweed allergen had higher rates of reactivity in high-pollen areas as compared with low-pollen areas 13.3 percent versus 7.2 percent). Skin-test reactivity was greater with higher income and education. Skin-test reactivity was greater in urban dwellers (22 percent) than in rural dwellers (16.5 percent). Skin-test reactivity was greatest in the Northeast (25.4 percent) and lowest in the South (14.2 percent).